Purchase of a Confocal Laser Scanning Microscope (CLSM) system, to be installed in the Department of Anatomy and Neurobiology at the University of Tennessee, Memphis is proposed. The CLSM will facilitate morphological investigation of central nervous system (CNS) function and structure by providing types of analyses that cannot be done with currently available light or electron microscopic techniques. Ongoing NIH-funded studies in the Department utilize fluorescent and non- fluorescent pathway tracers, cell markers, and histochemical labels throughout the CNS. Analyses include identification, localization, characterization and measurement of related CNS structures. The Bio-Rad MRC-600 CLSM system features an Argon/Krypton laser with wavelengths of 488, 568 and 647 nm permitting single-triple labeling, and 2 detection channels for simultaneous double label imaging; each channel features a selectable aperture and analog adjustment of signal dynamic range. The system will be operated by a Gateway PC/AT 486 compatible computer; an external WORM drive with separate cartridges for each User will provide long-term storage. The MS-DOS system will operate Bio-Rad's user-friendly windows-based software for acquisition, processing, and quantification of images in 2 and 3 dimensions. Additional software is available for 3-dimensional rotation and quantification. A epifluorescence microscope with several filter sets and a range of high numerical aperture objectives will be purchased. An identical second Bio-Rad computer workstation with a WORM drive will serve the 4 following functions: providing a training facility, transmitting files via Ethemet, permitting off-line data analysis for non-networked Users, and permitting off-line data analysis for Users without PC/AT computers. This will permit the operating computer with confocal image capture system to remain available for the primary purpose of image generation. The system package includes installation, training, software updates and a 1 year warranty. The second Bio-Rad computer workstation will be networked to a subnet of the Ethernet backbone at The University of Tennessee, Memphis that already transmits video images from an electron microscope, a Macintosh IIci image analysis workstation using programs such as the NIH IMAGE software, and a PC/AT compatible workstation using the Eutectics Neuron Tracing System; networking will allow Users to interface confocal images with a variety of software packages for image analysis as well as presentation.